Even if it's not needed that soon, it seems inevitable that there will be an eventual requirement for it.

A quote from the above article: "A study of the roads and motorways leading to Dublin Airport will also get under way immediately to find a location for the new terminal that would be best served by the road network."

It would seem incredibly short sighted not to include the planned Metro line in consideration of a future terminal 3. It seems likely the eventual site will be remote from the current terminals, therefore transport between the terminals should be an important consideration.

As construction work has not yet started on the Metro line, it would seem an ideal opportunity for some joined up thinking. If the preferred site for T3 can be identified, the Metro's route through the airport can be adjusted to allow a station for T3. Building a station box during the line's construction would be far cheaper than adding one later.

Having T3 served by Metro would reduce need for more vast car parks to be built at Dublin airport, reduce pressure on the road network, and could be an ideal route for passengers to transfer between T1/2 and T3.

It is important that this be considered before Metro construction gets underway.